This is a Cipher Liar Yajisan-Kazusan.
The rules for Yajisan-Kazusan can be found here: Rules page
In addition to the usual rules of Yajisan-Kazusan, one clue in every row and every column is mislabelled. If this clue is unshaded, then it does not point to the number of black squares indicated. If it is shaded, then it provides no information.
In addition, each number has been replaced by a letter. Different letters refer to different numbers.
Happy 50th puzzle! Here’s a simple one to celebrate.